DP20 Necrobiotic santhogranuloma of the scalp with nonprogressive thrombocytopenia: a case report

Abstract We present the case of an 84-year-old woman referred with a 6-month history lesion on her occipital scalp. Examination revealed creamy-white, nonscaly nodule measuring 15 × mm surface telangiectasia. Her past medical included basal cell carcinoma, stage 3 kidney disease, cardiovascular disease and osteoporosis. A diagnosis necrobiotic xanthogranuloma (NXG) was confirmed incisional biopsy, patient went to have full excision. Given association haematological malignancies, following discussion our local haematologist, investigations blood count, bone profile, immunoglobulins, serum urinary protein electrophoresis free light chains. This low platelet count 108 109 cells L–1 (reference interval 150–450) but no other significant abnormalities. Our haematologist considered marrow after patient, this declined. Necrobiotic is rare non-Langerhans histiocytosis. It classically presents as yellow, red or purplish papule in periorbital region, so had unusual site. The mean age onset sixth decade life, equal sex distribution. Pathogenesis unknown. associated particularly paraproteinaemia lymphoproliferative disease. Differential diagnoses include xanthelasma, chronic lupus erythematosus, sarcoidosis necrobiosis lipoidica. Where lesions become infiltrative plaque-like, mycosis fungoides psoriasis can also be considered. relatively nature NXG, there consensus for optimal treatment. In localized skin such surgical excision often undertaken. Other reported treatments are directed at chlorambucil small-dose corticosteroids, cyclophosphamide, melphalan, azathioprine, thalidomide, interferon-α intravenous immunoglobulin. Classical features histology palisading xanthogranulomas foci mid-dermis diffuse granulomatous panniculitis foreign body-type reaction Touton giant cells. slides showed atrophic epidermis dense dermal subcutaneous infiltrate consisting lymphocytes, foamy macrophages, plasma Touton-type multinucleate areas necrobiosis. There were reactive lymphoid follicles germinal centres. internal malignancy, it important diagnose these correctly. To date, has not developed any although increased risk future been counselled monitored accordingly. remains unclear whether presence thrombocytopenia alongside NXG coincidental finding marker published reports association.